Grinding wheel



J. F. FISCHER GRINDING WHEEL June 2l 1938.

Filed March 12, 1938 ,ZLIK

Patented June 21, 1938 UNITED STATES 2,121,656 U GRINDING WHEEL John F. Fischer, Drexel Hill, Pa., assignor to Abrasive Company, Philadelphia, Pa., a corporation of Pennsylvania Application March 12,

4 Claims.

Grinding wheels of the type mentioned are generally bonded of synthetic resins, rubber, shellac, and like materials and for the most part are employed in highspeed work. Usually molded grinding wheels bonded of synthetic resins, rubber, shellac, etc., are reinforced by means ,of rings which are embedded wholly within the wheel for the purpose of strengthening the same against bursting and preventing the fragments of the wheel from flying asunder when a fracture occurs, and while such rings are effective to some extent, they have certain disadvantages in that the wheels must be fabricated of superimposed layers to permit insertion of the rings and also it is difficult to produce such a grinding wheel which has the high degree of balance desired or required. Furthermore, such rings are wholly embedded within the wheel and therefore afford no visible assurance to an operator that such wheel is reinforced.

With the foregoing observations in mind, the principal .object of the present invention is to provide a molded grinding wheel wherein novel reinforcing means are provided and constructed and arranged with respect'to said wheel so as to afford greater holding power and reinforcement against bursting as the wheel is worn down and the speed of rotation increased.

Another object of the invention is to provide a molded grinding wheel of the character set forth having novel reinforcing means permanently associated therewith and constructed and arranged so as to insure a substantially perfect balanced wheel while permitting unitary or composite fabrication thereof.

These and other objects of the invention and the features and details'of .construction'thereof are hereinafterfully set forth and shown in the accompanying drawing, in which:

Figure 1 is a view in perspective of a grinding wheel made according to and embodying the present invention; p

Figure 2 is a view in section diametrically through the grinding wheel shown in Figure 1;

and

Figure 3 is a view similar to Figure 2 showing a modification or modified form of the invention.

wheel composed of suitable material bonded to- Referring now more particularly to the draw- 1938, Serial No. 195,632

gether by synthetic resins, rubber, shellac or other suitable substance and shaped into annular form.by means of a mold in the conventional manner.

Embedded and bonded into the grinding wheel I during molding thereof are two reinforcing elements 2 and 3 respectively of annular form each having a substantially channel shaped cross section. As shown in Figure 2 of the drawing, the reinforcing elements 2 and 3 each comprise a web portion 4 and flanges 5 and 6 which project substantially at right angles from said web portion 4 at opposite edges thereof. The reinforcing elements 2 and 3 are embedded in opposite faces or sides of the grinding wheel I immediately adjacent and surrounding the central opening therein in such manner that'the outer surfaces of the web portions I and flanges 6 reside respectively flush with or in the plane of the side faces and the wall surface of the central opening of the wheel, while the flanges 5 extend inwardly of the grinding wheel between its inner and outerperipheries substantially parallel to its axis of rotation. 5

From the foregoing description it will be seen that the reinforcing elements 2 and 3 become an integral part of the grinding wheel I and although the outer surfaces of. the web and flange portions 4 and 6 are exposed to view, the material of the grinding wheel is securely bonded to the innersurfaces of said web and flange portions 4 and 6 and is keyed to the'elements 2 and 3 respectively by means of the inwardly extending flange portions 5 thereof which extend parallel to the axis of rotation of the wheel and oppose the action of centrifugal force thereon.

A grinding wheel constructed according tothe present invention is preferably supported for rotation between a pair of plates or disks 1 shown in dot and dash lines in Figure 2 of the drawing which grip opposite sides of the grinding wheel at the exposed web portion 4 of the reinforcing elements 2 and 3. The diameter of these supporting disks 1 is slightly less than the outside diameter of the reinforcing elements 2 and 3 so as to not project therebeyond and the disks 1 are further provided with annular flanges 8 arranged to fit snugly within the central opening in the grinding wheel in engagement with the surface of the flanges 6 of the reinforcing elements 2 and 3 asshown, thus properly centering the wheel I with respect to the disks 1 and the axis of theopenings 9 therein through which extends the shaft for driving said wheel.

A modification oi' the invention is shown in Figure 3 of the drawings and in this particular embodiment thereof the flanges 6a of the reinforcing elements 2a and 3a are appreciably longer and the inner portion of the flange 6a of the ele-- ment 3a. is offset radially as indicated at W to receive the overlapping portion of the flange 6aof the element 2a thus providing a wall or lining of uniform bore or diameter for the central opening in the grinding wheel I. In cther'respects the reinforcing elements 2a and 3a are. identical to the elements 2 and 3 previously described.

In addition to providing maximum reinforcement and more accurate balance in grinding wheels of the present character, the elements 2' and 3 or 2a and 3a function to protect the edges of the wheel at the central opening therein during the molding operation and mounting of the wheel for use. These reinforcing elements also serve to reduce wear in the mounting equipment and'also provide a metal to metal contact between the grinding wheel and its mounting. Furthermore, the exposed surfaces of the web portions 3 of the reinforcing elements afford solid plane bearing surface at opposite sides of the wheel for the disks 7 and in addition serve as a positive indication to the user of thewheel that suitable reinforcing means are embodied therein.

The invention, of course, is not limited to high speed grinding wheels but may be embodied as desired in molded grinding wheels of any type for any use or work, and while certain specific embodiments of said invention have been illustrated and described herein, it is not intended that the invention shall be limited thereto but that changes and modifications may from time to time be incorporated and embodied therein within the scope of the annexed claims.

I claim:

1. A molded article of the character described comprising an annular body member, and an'annular reinforcing element embedded and bonded in each side face of said annular body member immediately adjacent and surrounding the central opening, therein, said reinforcing elements each including a web portion disposed flush in a side face of the body member, an edge flange lining at least a portion of the central opening of said body member, and a portion projecting into the body member substantially parallel to its axis of rotation.

2. A molded article of the character described comprising an annular body member, and an annular reinforcing element embedded and bonded in each side face of said body member immediatemenace ly adjacent and surrounding the central opening therein, said reinforcing elements each including a web portion disposed flush in a side face of the body member, an edge flange lining at least a portion of the central opening of said body member, and a, portion projecting into the body member substantilly parallel to its axis of rotation, the edge flanges of the reinforcing elements overlapping one another alongthe wall ofthe central opening and one of said flangesbeing 'ofiset radially to receive the lapping portion of the other to provide a lining for the central opening of substantially uniform diameter.

3. A molded article of the character described comprising an annular body member, an annular reinforcing element embedded and bonded in each side face ofsaid body member immediately adjacent and surrounding the central opening therein, said reinforcing elements each including a web portion disposed flush in aside face of the body member, an edge flange lining at least aportion of'the central opening'of said body member, and a portion projecting into the body member substantially parallel to its axis of rotation, and mounting disks secured to opposite side faces of said body member centrally thereof and engaging the web portions of the reinforcing elements, said disks each having a flange thereon fitting snugly within the lining of central opening of the body member.

4i. A molded article of the character described comprising'an annular body member, an annular reinforcing element embedded and bonded in each side face of said body member immediately adjacent and surrounding the central opening therein, said reinforcing elements each including a web portion disposed flush in a side face of the body member, an edge flange lining at least a poruniform diameter, and mounting disks secured to opposite side faces of said body member ceritrally thereof and engaging the web portions of the reinforcing elements, said disks each having a flange thereon fitting snugly within the lining of the central opening of the body member.

JOHN F. FISCHER. 

